We impose an intensity ordering on event types which sets us apart from [1]}, [2]}, [3]}, [4]} who assume unordered categorical event types, but still evaluate their latent states against the ordered Goldstein scale in the case of [1]}. [6]} measure interstate hostility at the country dyad-quarter level. They use an item response theory (IRT) model based on an ordered logistic regression. Treating international relations as latent, unordered states in an Hidden Markov Model is an established modeling idea [7]}, [8]}, [9]}. [9]} pre-specify four latent states: peace, conflict, escalation, and de-escalation, and strictly band transitions. This is reminiscent of Kahn's Escalation Ladder [11]}, [12]} that defines stages and thresholds of conflict. Neural network-based approaches focus on modeling friend-enemy relationships [13]}, [14]}. The tracing of conflict escalation has also been studied in word embeddings [15]} and language models [16]}, [17]}.
